.middle > div {
    border: 1px solid gray;
}

.online {
    display: flex;
    justify-content: center;
}

.online > div {
    width: 700px;
    /*border: 1px solid red;*/
}

.online > div > div:nth-child(1) {
    font-size: 10px;
    /*字体居中,只能对字体有效，不能控制div*/
    text-align: center;
    margin: 30px 0;
}

/*我们会做的更好!WE WILL DO BETTER*/
.online > div > div:nth-child(1) > div:nth-child(1) {
    display: flex;
    justify-content: center;
    align-items: center;
}

.online > div > div:nth-child(1) > div:nth-child(1) > div:nth-child(1) {
    color: rgb(230, 145, 55);
    font-size: 30px;
}

.online > div > div:nth-child(1) > div:nth-child(1) > div:nth-child(2) {
    color: gray;
}

/*------------------form------------------*/
.form {
    display: flex;
    justify-content: center;
}

.form > div {
    width: 600px;
    /*border: 1px solid red;*/
}
.form > div > div:nth-child(1) > div > div:nth-child(1){
    line-height: 30px;
}
/*元素选择器*/
/*，分组选择器*/
/*input[required]属性选择器*/
input[required], textarea {
    height: 30px;
    border: 1px dashed gray;
    background-color: rgb(238, 238, 238);
    line-height: 30px;
    padding: 0 10px;
    width: 580px;
}

textarea {
    height: 100px;
    line-height: 20px;

}
form>div>div:nth-child(2){
    display: flex;
    justify-content: center;
}
input[type=submit]{
    background-color:rgb(230, 145, 55);
    margin: 30px 0;
    padding: 10px 50px;
    color: white;
    border: none;
    cursor: pointer;
    border-radius: 40px 40px;
    box-shadow: 1px 1px 5px 1px rebeccapurple;
}
